There's a story making its rounds across the 'net about a woman who missed several online classes, and failed her semester, and she claims this happened because she bought a Dell laptop with Ubuntu on it - instead of Windows. She didn't know what Ubuntu was, and was surprised to see that her Windows software, such as Microsoft Office, didn't work. While this isolated case sounds a bit ridiculous, there is still a bigger problem here.

Of course, you shouldn't try to force some format, operating system, whatever on your students. On the other hand, a university simply cannot support everything (including several operating systems) either. Otherwise, the next guy comes with his Haiku laptop and rants about the uni not supporting his OS.

My point is: A computer is a tool. When you need to buy a tool for doing some kind of work, you make sure it is the appropriate one. Would you blame the manufacturer of screws that you can't use a hammer to get them into your walls? No. So in conclusion, I think it's mainly the woman's fault for not checking if her tool suits the job. But there maybe is some fault on the university's side, too, because they didn't provide a proper "tool requirement" list.

As for Dell, if it's their experience that customers get along very well with Linux, I think it's perfectly reasonable for them to encourage you to use it. They can't know about the support for Linux of any university in the world.